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Understanding the mechanism that controls cement hydration and its stages is a long-standing challenge. Over a decade ago, the mineral dissolution theory was adopted from geochemistry to explain the hydration rate evolution of alite. The theory is not fully accepted by the community and deserves further investigation. In this work, we apply Kinetic Monte Carlo (KMC) simulations with the mineral dissolution theory as a conceptual framework to investigate and discuss alite dissolution. We build a Kossel crystal model system and parameterize the dissolution activation energies and frequencies based on experimental data. The resulting KMC model is capable of reproducing the dissolution rate and activation energies as a function of the dissolution free energy. The simulations indicate that mineral dissolution theory easily explains the induction and acceleration stages due to a continuous increase of the reactive area as the etch pits open. However, the deceleration stage is hardly reconcilable with the mechanism suggested in the literature, i.e. dislocation coalescence. Still, within the mineral dissolution theory umbrella, we propose and discuss an alternative mechanism based on dislocation exhaustion. 

We develop Mg/C/O/H ReaxFF parameter sets for two environments: an aqueous force field for magnesium ions in solution and an interfacial force field for minerals and mineral–water interfaces. Since magnesium is highly ionic, we choose to fix the magnesium charge and model its interaction with C/O/H through Coulomb, Lennard-Jones, and Buckingham potentials. We parameterize the forcefields against several crystal structures, including brucite, magnesite, magnesia, magnesium hydride, and magnesium carbide, as well as Mg 2+ water binding energies for the aqueous forcefield. Then, we test the forcefield for other magnesium-containing crystals, solvent separated and contact ion-pairs and single-molecule/multilayer water adsorption energies on mineral surfaces. We also apply the forcefield to the forsterite–water and brucite–water interface that contains a bicarbonate ion. We observe that a long-range proton transfer mechanism deprotonates the bicarbonate ion to carbonate at the interface. Free energy calculations show that carbonate can attach to the magnesium surface with an energy barrier of about 0.22 eV, consistent with the free energy required for aqueous Mg–CO 3 ion pairing. Also, the diffusion constant of the hydroxide ions in the water layers formed on the forsterite surface are shown to be anisotropic and heterogeneous. These findings can help explain the experimentally observed fast nucleation and growth of magnesite at low temperature at the mineral–water–CO 2 interface in water-poor conditions.